title: Interfacial protein engineering for spray-dried emulsions - part II: oxidative stability.
abstract: The aim of this work was to investigate how the oxidative stability of encapsulated oil is affected by the humidity response of a Na-caseinate-maltodextrin matrix. Furthermore, the effect of modification of the interfacial Na-caseinate layer through cross-linking was studied. For this purpose, two model spray-dried emulsions containing sunflower oil, maltodextrin, and either non-cross-linked or cross-linked Na-caseinate were stored at different relative humidities (RHs; ∼0%, 11%, 33%, 54%, and 75%). Increasing RH improved the oxidative stability of the spray-dried emulsions. This behaviour was mainly linked to the loss of individual powder particles upon caking and collapsing of the matrix at RH 75%. Oxidation of non-encapsulated surface lipids with a proportion of ca. 5% of total lipids was only twofold compared to total lipids. Excess protein on particle surfaces may have delayed oxidation, e.g., by its radical scavenging activity. Under several storage conditions, cross-linking of the protein slightly improved the oxidative stability.
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland. Electronic address: annelie.damerau@helsinki.fi.
authors.forename: Annelie
authors.initials: A
authors.lastname: Damerau
authors.forename: Timo
authors.initials: T
authors.lastname: Moisio
authors.forename: Riitta
authors.initials: R
authors.lastname: Partanen
authors.forename: Pirkko
authors.initials: P
authors.lastname: Forssell
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Lampi
authors.forename: Vieno
authors.initials: V
authors.lastname: Piironen
mesh_terms: D002364:Caseins / Q000737:chemistry*; D003890:Desiccation; D004655:Emulsions / Q000737:chemistry*; D005524:Food Technology; D010084:Oxidation-Reduction; D010938:Plant Oils / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D011208:Powders / Q000737:chemistry; D000074242:Sunflower Oil
chemical_list: D002364:Caseins; D004655:Emulsions; D010938:Plant Oils; D011134:Polysaccharides; D011208:Powders; D000074242:Sunflower Oil; C008315:maltodextrin
keywords: Cross-linking; Maltodextrin–Na-caseinate; Oxidation; Spray-dried emulsion; Sunflower oil